Abstract: A counter abstraction tool generates an abstraction model for one or more counters in a circuit design for use with a formal verification system. The tool detects the presence of a counter in a circuit design, identifies one or more special values for the counter, and creates an abstraction for the counter. The tool can automatically perform the abstraction, guide a user in configuring the appropriate abstraction for the counter, or perform a combination of automatic and manual abstraction. The tool may further accommodate related counters.

Abstract: A method includes grouping cells with similar topological characteristics into a family of cells, the topological characteristics being defined in part by topological layouts of transistors in the respective cells in the family of cells; and computing data characterizing a relationship between a variability of delay and a magnitude of delay shared among the cells in the family of cells.

Abstract: A method and apparatus for retrofitting semiconductor chip performance analysis tools with full-chip thermal analysis capabilities is provided. One embodiment of a novel method for performing performance analysis of a semiconductor chip design includes receiving at least one input calculated in accordance with an actual (e.g., purposefully calculated rather than assumed or estimated) temperature of a semiconductor device and/or an interconnects in the semiconductor ship design. This input is then used to assess at least one temperature-dependent performance parameter of the semiconductor chip design.

Abstract: A method and apparatus for full-chip thermal analysis of semiconductor chip designs is provided. One embodiment of a novel method for performing thermal analysis of a semiconductor chip design comprises receiving at least one input relating to a semiconductor chip design to be analyzed. The input is then processed to produce a three-dimensional thermal model of the semiconductor chip design. In another embodiment, thermal analysis of the semiconductor chip design is performed by calculating power dissipated by transistors and interconnects included in the semiconductor chip design and distributing power dissipated by the interconnects.

Abstract: For application to analog, mixed-signal, and custom digital circuits, a system and method to begin with a complex problem description that encompasses many variables from statistical manufacturing, the circuit's environment, and the circuit's design parameters, but then apply techniques to prune the scope of the problem to make it manageable for manual design and more efficient automated design, and finally use that pruned problem for more efficient and effective design.

Abstract: For accomplishing a circuit design, a first physical design is implemented according to a first netlist to obtain a first physical layout of a circuit. The first physical layout of the circuit is processed to obtain a first timing data. The first timing data is then inputted for timing verification of the first netlist. If the first netlist does not pass the verification, the first netlist is modified into a second netlist, while defining a modified portion of the netlist. Then, the modified portion of netlist is processed to obtain a second timing data, and the second timing data is used to overwrite a part of the first timing data. The first physical design is modified into a second physical design according to the second netlist only when the second netlist with the first timing data overwritten by the second timing data passes the timing verification, thereby improving time efficiency.

Abstract: While performing functional verification on a circuit design, a verification tool allows a user to analyze the results of a previous functional analysis. The tool may also receive commands for a next verification analysis while performing a current analysis, and it may allow a user to abort a current analysis. Results from a completed analysis may be discarded or saved for viewing by a user while a next verification is performed on the circuit design. This allows a user to continue to debug and analyze the circuit design without having to wait until previous steps in the verification analysis are completed.

Abstract: A thermally aware design automation suite integrates system-level thermal awareness into the design of semiconductor chips. A thermal analysis engine performs fine-grain thermal simulations of the semiconductor chip based on thermal models and boundary conditions for all thermally significant structures in the chip and the adjacent system that impact the temperature of the semiconductor chip. The thermally aware design automation suite uses the simulations of the thermal analysis engine to repair or otherwise modify the thermally significant structures to equalize temperature variations across the chip, impose specified design assertions on selected portions of the chip, and verify overall chip performance and reliability over designated operating ranges and manufacturing variations. The thermally significant structures are introduced or modified via one or more of: change in number, change in location, and change in material properties.

Abstract: A method of optimizing clock-gated circuitry in an integrated circuit (IC) design is provided. A plurality of signals which feed into enable inputs of a plurality of clock gates is determined, where the clock gates gate a plurality of sequential elements in the IC design. Combinational logic which is shared among the plurality of signals is identified. The clock-gated circuitry is transformed into multiple levels of clock-gating circuitry based on the shared combinational logic.

Abstract: A power optimization method of deriving gated circuitry in a synthesized netlist of an integrated circuit (IC) design is provided. A block in the synthesized netlist is identified as an idle candidate block. Sub-blocks on the chip are clustered into a cluster. For the cluster, a clock gating structure optimized for power savings is determined, based on the idle candidate block. One or more inflexible clock gates are inserted in the netlist according to the clock gate structure.

Abstract: Methods for optimizing design parameters of a circuit are disclosed. In one aspect, an optimization problem includes one or more performance specifications that represent an exponent of a design parameter to be optimized. Various parameters of passive and active circuit devices may be efficiently and accurately optimized as a result. In another aspect, linear performance specifications are included for accurately calculating voltages. In yet other aspects of the invention, three special types of convex optimization problems are disclosed for enabling the above use of exponents of design parameters which provide efficient and accurate calculations of a virtually unlimited array of circuit parameters and performance characteristics.

Abstract: A system and a method are disclosed for circuit analysis. A circuit modeling system calculates sensitivities of gates for statistical static timing analysis of a circuit. Timing distribution sensitivities of gates and correlations between the sensitivities are determined. A Monte Carlo simulation is run using the sensitivities to determine timing distribution of paths and determine probabilities of paths being the critical path. Aggregate sensitivities for cells are also determined.

Abstract: A method and apparatus for normalizing thermal gradients over semiconductor chip designs is provided. One embodiment of a novel method for normalizing an expected thermal gradient includes determining a location of the thermal gradient in the semiconductor chip design and inserting at least one supplemental heat source into the semiconductor chip design such that the thermal gradient is normalized by heat dissipated by the supplemental heat source.

Abstract: A method for generating a layout for an analog circuit design is provided. The method includes tracing a signal flow through a circuit netlist, and partitioning the circuit netlist into a digital portion and an analog portion. A signal flow is defined through the analog portion of the circuit netlist. A system for generating a layout for an analog circuit design is also included.

Abstract: A system and a method are disclosed for integrating the results of lithographic simulation into the physical synthesis process. The effects of lithographic variation are considered when selecting a cell from among a group of cells having equivalent function. Circuit design elements are placed and routed with consideration of the effects of lithographic variation on robustness, timing performance, and leakage current. Cells may be simulated under a variety of conditions and environments and the simulation results stored in a library for efficient lithographically optimized placements.

Abstract: A property used in functional verification of a circuit design is debugged independently of the circuit design for which the property is intended. Visualization of the property under various conditions helps a user to debug any errors in how the property is implemented in a requirements model. To visualize a particular property, a trace of a corresponding property in the requirements model is generated. The trace illustrates waveforms of a set of signals related to the property for a number of clock cycles. To visualize the property under various conditions, a user can find additional traces of the property by applying visualization constraints to obtain meaningful traces.

Abstract: A counter abstraction tool generates an abstraction model for one or more counters in a circuit design for use with a formal verification system. The tool detects the presence of a counter in a circuit design, identifies one or more special values for the counter, and creates an abstraction for the counter. The tool can automatically perform the abstraction, guide a user in configuring the appropriate abstraction for the counter, or perform a combination of automatic and manual abstraction. The tool may further accommodate related counters.

Abstract: Methods and systems for electronic design automation includes clustering objects into more manageable numbers of objects. Clustering is optionally performed to reduce or minimize interconnections between clusters. Clustering optionally includes multi-level clustering. The clusters, and any unclustered objects, are floorplanned. Floorplanning positions the clusters so as to reduce or minimize the length of interconnections between the clusters. Objects within the clusters are then placed within the area assigned to the corresponding clusters. Placement optionally utilizes placement-based wire load models to accurately predict timing issues. A bottoms-up procedure is optionally performed during clustering and/or floorplanning, whereby area and/or size constraints of clustered objects are taken into account.

Abstract: A method and apparatus for modeling and thermal analysis of semiconductor chip designs is provided. One embodiment of a novel method for performing thermal testing of a semiconductor chip design includes calculating full-chip temperatures over the semiconductor chip design (e.g., to identify steep thermal gradients) and modeling the full-chip temperatures in accordance with a geometric multi-grid technique. The geometric multi-grid technique is tailored to determine temperatures within the semiconductor chip design based at least in part on the physical attributes or geometry of the design.

Abstract: A method of efficient library characterization of a circuit of a logic gate having a plurality of transistors and a plurality of nodes defining interconnection points in the circuit is disclosed. The method includes determining a plurality of vectors for a plurality of arcs. Each of the plurality of vectors represents possible data bits to inputs and nodes of the logic gate. The method selects a plurality of substantially distinct vectors from the plurality of vectors for each of the plurality of arcs, and performs circuit pruning for each of the plurality of substantially distinct vectors, taking each one substantially distinct vector at a time. The circuit pruning includes identifying an active circuit for each vector. The active circuit is identified by determining which circuit features are activated when applying a particular one of the substantially distinct vectors. Then, the circuit simulations limited to a plurality of transistors in the active circuit are performed.